P10 - Pulmonary pathology

Question 1

What are clinical presentations of lung disease?

Answer 1

• Cough, wheeze
• Breathlessness (dyspnoea)
• Chest pain (often due to pleural disease)

Question 2

Are the lungs themselves sensitive to pain?

Answer 2

No- but the chest wall is

Question 3

What are the 2 functional classifications of lung disease?

Answer 3

• Obstructive

- Restrictive

Question 4

Describe obstructive lung disease.

Answer 4

Normal volume but difficulty getting air out (asthma)

Question 5

Describe restrictive lung disease.

Answer 5

Decreased lung volumes (scarring /fibrosis in lungs)

Question 6

Name 5 ways of investigation of a patient with lung disease.

Answer 6

• Chest x-ray +/- CT scan
• Hb, white cell count etc
• Arterial blood gases (pO2, pCO2, pH)
• Physiology (spirometry, pulmonary function tests)
• Bronchoscopy +/- biopsy and lavage

Question 7

what is the lungs function?

Answer 7

to facilitate transfer of O2 to blood and CO2 in the other direction

Question 8

What is type 1 respiratory failure?

Answer 8

decreased arterial pO2

Question 9

What is type II respiratory failure?

Answer 9

decreased arterial pO2 plus increased arterial pCO2

Question 10

which is worse of the two respiratory failures?

Answer 10

Type II - pulmonary function is terminal

Question 11

What does decreased Pa O2 lead to?

Answer 11

• Dyspnoea and increased respiratory rate
• Pulmonary vasoconstriction (and pulmonary
hypertension)
• Eventually right sided heart failure

Question 12

What can cause airway narrowing /obstruction?

Answer 12

• Muscle spasm
• Mucosal oedema (inflammatory or otherwise
• Airway collapse due to loss of support
• (Localised obstruction due to tumour or foreign body)

Question 13

What are the main categories of obstructive disease?

Answer 13

• Asthma

* Chronic obstructive pulmonary disease (COPD/COAD/COLD)

Question 14

What is bronchial asthma?

Answer 14

A chronic inflammatory disorder characterised by hyperreactive airways leading to episodic reversible bronchoconstriction

Question 15

What is extrinsic asthma?

Answer 15

response to inhaled antigen

Question 16

What is intrinsic asthma?

Answer 16

non-immune mechanisms (cold, exercise, aspirin)

Question 17

What is type I hypersensitivity ?

Answer 17

Allergen binds to IgE on surface of mast cells

Question 18

what effects does type 1 hypersensitivity have?

Answer 18

• Degranulation (histamine)
– muscle spasm
– inflammatory cell influx (eosinophils)
– mucosal inflammation/oedema
• Inflammatory infiltrate tends to chronicity

Question 19

Name the types of pathology.

Answer 19

• Narrowed oedematous airways
• Mucus plugs
• Inflammatory cells (lymphocytes, plasma cells, eosinophils)
• Epithelial cell damage

Question 20

What is mucosal oedema?

Answer 20

airways narrowed and blocked by mucous

Question 21

Name 2 types of chronic obstructive disease.

Answer 21

• Chronic bronchitis

* Emphysema

Question 22

what do symptomatic patients have?

Answer 22

Often have both chronic bronchitis and emphysema

Question 23

What is the epidemiology of COPD?

Answer 23

• Smoking
• Atmospheric pollution
• Genetic factors

Question 24

what is the epidemiology definition of chronic bronchitis?

Answer 24

Cough productive of sputum on most days for 3 months of at least 2 successive years

Question 25

what does chronic bronchitis not imply?

Answer 25

airway inflammation

Question 26

What is emphysema?

Answer 26

• Increase beyond the normal in the size of the airspaces distal to the terminal bronchiole • Without fibrosis -The gas-exchanging compartment of the lung

Question 27

What is emphysema due to?

Answer 27

“Dilatation” is due to loss of alveolar walls (tissue destruction) • Appears as “holes” in the lung tissue

Question 28

Discuss the diagnosis and treatment of emphysema.

Answer 28

• Difficult to diagnose in life (apart from in extremis) • Radiology (CT) can show changes in lung density • Correlation with function known from autopsy studies

Question 29

what is panacinar emphysema?

Answer 29

Tissue destructtion-extreme -big dilated airspaces, loss of tissue between gives illusion of dilation

Question 30

what do emphysema impair?

Answer 30

respiratory function

Question 31

How does emphysema impairs respiratory function?

Answer 31

* Diminished alveolar surface area for gas exchange | * Loss of elastic recoil and support of small airways leading to tendency to collapse with obstruction

Question 32

What causes restrictive lung disease?

Answer 32

* Decreased lung volumes due to scarring +/- inflammation in the alveolar walls * Many causes (idiopathic pulmonary fibrosis, sarcoidosis, farmer’s lung, asbestosis)

Question 33

Name 3 pulmonary infections.

Answer 33

* Pneumonia * Chronic infection – abscess/bronchiectasis * Tuberculosis

Question 34

what is pneumonia?

Answer 34

Infection involving the distal airspaces usually with inflammatory exudation (“localised oedema”) -fluid filled spaces lead to consolidation

Question 35

what is bronchopneumonia?

Answer 35

Common in older people -after flu - common terminal cause of death

Question 36

what is the clinical context of bronchopneumonia?

Answer 36

* COPD * Cardiac failure (elderly) * Complication of viral infection (influenza) * Aspiration of gastric contents

Question 37

Name 4 complications of pneumonia.

Answer 37

* Scarring * Abscess * Bronchiectasis * Empyema (pus in the pleural cavity)

Question 38

Describe lung abscess.

Answer 38

* Localised collection of pus •Tumour-like | * Chronic malaise and fever •Context - aspiration

Question 39

what is tuberculosis?

Answer 39

* Mycobacterial infection | * Chronic infection described in many body sites – lung, gut, kidneys, lymph nodes, skin

Question 40

what is tuberculosis pathology characterised by?

Answer 40

delayed (type IV) hypersensitivity (granulomas with necrosis)

Question 41

what are the 2 types of lung neoplasm?

Answer 41

- Primary | - Metastatic

Question 42

What are the 2 types of primary lung neoplasms.

Answer 42

– benign (rare) | – malignant (very common)

Question 43

What is metastatic?

Answer 43

coming from somewhere else in the body

Question 44

what is the commonest cause of cancer death in men?

Answer 44

33% in men

Question 45

what is the mortality rate 1 year after diagnosis?

Answer 45

90%

Question 46

What does tobacco smoke contain?

Answer 46

* polycyclic hydrocarbons * aromatic amines * phenols * nickel * cyanates

Question 47

What percentage of smokers die of lung cancer and what do they also suffer from?

Answer 47

- 20% of smokers die of lung cancer | - (also suffer laryngeal, cervical, bladder, mouth, oesophageal, colon cancer)

Question 48

What is the clinical presentation of a primary neoplasm?

Answer 48

Local effects: - obstruction of airway (pneumonia) - invasion of chest wall (pain) - ulceration (haemoptysis

Question 49

What is the clinical presentation of metastases?

Answer 49

– nodes – bones – liver – brain

Question 50

How many common smoking -associated lung tumours are there (heterogenous)?

Answer 50

``` 4: – adenocarcinoma (35%) – squamous carcinoma (30%) – small cell carcinoma (25%) – large cell carcinoma (10%) ```

Question 51

what other classification of lung tumours are there?

Answer 51

* Neuroendocrine tumours | * Bronchial gland tumours

Question 52

what is different about different type of tumours?

Answer 52

Prognosis

Question 53

what is the most simple classification of lung cancer?

Answer 53

- Small cell lung cancer (SCLC) | - Non-small cell lung cancer (NSCLC)

Question 54

What is the treatment of small cell lung cancer?

Answer 54

* Small cell known to be chemosensitive but with rapidly emerging resistance * Surgery the treatment of choice in other types. “Non-small cell” regimens have also been developed in chemotherapy/radiotherapy

Question 55

What are new development in chemotherapy?

Answer 55

* Differing NSCLC regimens for squamous cell and adenocarcinoma (e.g. pemetrexed contraindicated in squamous carcinoma) * Molecular abnormalities, particularly in adenocarcinoma, can define susceptibility to new targeted drug treatments

Question 56

Describe the molecular pathology and targeted treatment (epithelial growth signalling in lung epithelium.

Answer 56

* Specific point mutations render the EGFR gene active in the absence of ligand (epidermal growth factor) binding * These mutations can be identified in DNA extracted from biopsy or cytology samples * Mutation seen almost exclusively in adenocarcinoma (esp. non-smokers and in Asian populations) * These tumours respond to tyrosine kinase inhibitors (erlotinib) * EML4-ALK fusion oncogene also identifies a target for specific drug treatment (crizotinib)